A headrest of the type described above has been disclosed in German Offenlegungsschrift DE-OS No. 31 03 620 for use with rear seats of station wagons. This prior art headrest is secured to an arm which is provided with a pivot joint and which in the head support position of the headrest is pulled by a tension-type coil spring into the sleeve member to a point where the pivot joint is locked and the headrest is sufficiently secured into position. The headrest is moved forwardly into a storage position by lifting the arm manually until the pivot joint is located above the edge of the backrest of the seat, whereupon the arm can be pivoted through an angle of 90.degree.. The tension-type spring is secured at a location above the pivot joint and thereby retains the headrest in the storage position. The disadvantage of this prior art headrest is that the fold-down operation is awkward, because the headrest must be raised against the force of the tension-type spring until the pivot joint is exposed before the headrest can be folded down. When the vehicle is fully loaded, it is difficult to fold down the headrest from any place other than the rear seat.
German Offenlegungsschrift DE-OS No. 31 36 648 discloses another headrest arranged inside the backrest of a motor vehicle seat which, through the use of a servo mechanism, is automatically pivoted into the head support position when the weight of the seat user is applied to the seat cushion of the associated vehicle seat, and is automatically returned into the storage position when the weight is removed, i.e., when the occupant leaves the seat. This arrangement provides that the headrest is in the head support position only when the seat is occupied. Since the headrest, during the time the seat is unoccupied, is in a lowered position, the driver of the vehicle is afforded a better view towards the rear. The power mechanism for this headrest includes an electric motor and a pinion gear which is in engagement with a gear segment. The gear segment is fixedly connected to the frame of the backrest, and the headrest is adapted for pivoting movement about the gear segment shaft disposed inside the headrest. The disadvantage of this prior art arrangement is that is it relatively complicated and expensive to manufacture, and that a special type of headrest is required which cannot always be replaced by a headrest of the ordinary type. Another disadvantage is that this headrest cannot completely be moved out of the field of view of the driver since it is pivoted only from its mounting position on top of the seat.
It is the object of the present invention to provide a foldable headrest of the type described above which is relatively simple in design and easy to operate, and which can be folded down to a position which is low enough to afford the driver of the vehicle an unobstructed view towards the rear.
In accordance with the invention, this object is achieved in that a push button actuated displacement mechanism is provided through which the pivot joint can be unlocked, and in that the bar, or an upper portion thereof, together with headrest can be automatically folded down.
The invention enables that, upon actuation of a push button, which may be disposed on the backrest of the seat or, for instance, on the dashboard, the headrest can be automatically moved from the head support position to the storage position in which the headrest is located below the upper edge of the backrest so as to afford the vehicle operator an unobstructed view towards the rear. Return movement of the headrest into the head support position is carried out, preferably, manually, with the displacement mechanism being activated at the same time. This arrangement provides an adjusting device which is easy to operate and which enables, if desired, automatic tilting of the headrest.